feat(conversion): add SVG to PDF conversion functionality (#5431)

# Description of Changes This pull request introduces a new SVG to PDF conversion feature, including both backend and frontend changes. The backend adds a secure, vector-preserving SVG-to-PDF conversion endpoint with comprehensive SVG sanitization to prevent XSS and SSRF attacks. The frontend is updated to route SVG-to-PDF conversions through this new endpoint and to distinguish SVG from other image formats. Additionally, a new dependency is added for PDF rendering. **Backend: SVG to PDF Conversion and Security** * Adds a new API endpoint and controller (`ConvertSvgToPDF`) for converting SVG files to PDF, using Batik and PDFBox with vector graphics preservation and robust error handling. * Implements SVG sanitization (`SvgSanitizer`) to remove scripts, event handlers, and dangerous URLs, protecting against XSS and SSRF attacks. * Introduces a utility (`SvgToPdf`) for rendering SVG to PDF with timeout protection against resource exhaustion attacks. * Defines a new request model (`SvgToPdfRequest`) for SVG to PDF conversion requests. * Adds the `pdfbox-graphics2d` dependency for vector graphics PDF rendering. **Frontend: Routing and Format Handling** * Updates conversion endpoint constants to add `svg-pdf` and maps SVG files to use the new `svg-to-pdf` route instead of the generic image-to-PDF route. * Removes SVG from the generic image format list and introduces a dedicated check for SVG format (`isSvgFormat`). <img width="1133" height="995" alt="image" src="https://github.com/user-attachments/assets/dec8cf27-ccb9-490d-af76-bff69feb0423" />  --- ## Checklist ### General - [X] I have read the [Contribution Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md) - [X] I have read the [Stirling-PDF Developer Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md) (if applicable) - [X] I have read the [How to add new languages to Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md) (if applicable) - [X] I have performed a self-review of my own code - [X] My changes generate no new warnings ### Documentation - [ ] I have updated relevant docs on [Stirling-PDF's doc repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/) (if functionality has heavily changed) - [ ] I have read the section [Add New Translation Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags) (for new translation tags only) ### Translations (if applicable) - [ ] I ran [`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md) ### UI Changes (if applicable) - [ ] Screenshots or videos demonstrating the UI changes are attached (e.g., as comments or direct attachments in the PR) ### Testing (if applicable) - [X] I have tested my changes locally. Refer to the [Testing Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing) for more details. --------- Signed-off-by: Balázs Szücs <[email protected]>
2026-07-16 03:20:46 +02:00 · 2026-01-16 18:45:50 +00:00
parent 3e061516a5
commit cb5c2a5803
17 changed files with 1150 additions and 27 deletions
@@ -0,0 +1,244 @@
+package stirling.software.SPDF.controller.api.converters;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.multipart.MultipartFile;
+
+import io.github.pixee.security.Filenames;
+import io.swagger.v3.oas.annotations.Operation;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.SPDF.config.swagger.MultiFileResponse;
+import stirling.software.SPDF.model.api.converters.SvgToPdfRequest;
+import stirling.software.SPDF.utils.SvgToPdf;
+import stirling.software.common.annotations.AutoJobPostMapping;
+import stirling.software.common.annotations.api.ConvertApi;
+import stirling.software.common.service.CustomPDFDocumentFactory;
+import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.SvgSanitizer;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
+import stirling.software.common.util.WebResponseUtils;
+
+@ConvertApi
+@Slf4j
+@RequiredArgsConstructor
+public class ConvertSvgToPDF {
+
+    private final CustomPDFDocumentFactory pdfDocumentFactory;
+    private final SvgSanitizer svgSanitizer;
+    private final TempFileManager tempFileManager;
+
+    @AutoJobPostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/svg/pdf")
+    @MultiFileResponse
+    @Operation(
+            summary = "Convert SVG to PDF",
+            description =
+                    "This endpoint converts one or more SVG (Scalable Vector Graphics) files to PDF format. "
+                            + "Each SVG is converted to a separate PDF file. "
+                            + "The conversion preserves vector graphics for crisp output at any resolution - no rasterization occurs. "
+                            + "SVG dimensions (width/height) determine the PDF page size; defaults to A4 if not specified. "
+                            + "SVG content is sanitized to prevent XSS attacks. "
+                            + "Input: SVG file(s), Output: PDF file(s) or ZIP. Type: MIMO")
+    public ResponseEntity<byte[]> convertSvgToPdf(@ModelAttribute SvgToPdfRequest request) {
+
+        MultipartFile[] inputFiles = request.getFileInput();
+        boolean combineIntoSinglePdf = Boolean.TRUE.equals(request.getCombineIntoSinglePdf());
+
+        // Validate input
+        if (inputFiles == null || inputFiles.length == 0) {
+            log.error("No files provided for SVG to PDF conversion.");
+            return ResponseEntity.badRequest()
+                    .body("No files provided".getBytes(StandardCharsets.UTF_8));
+        }
+
+        try {
+            List<byte[]> sanitizedSvgs = new ArrayList<>();
+            List<String> filenames = new ArrayList<>();
+
+            for (MultipartFile inputFile : inputFiles) {
+                if (inputFile == null || inputFile.isEmpty()) {
+                    log.warn("Skipping empty file in batch conversion");
+                    continue;
+                }
+
+                String originalFilename = inputFile.getOriginalFilename();
+                if (originalFilename == null || originalFilename.trim().isEmpty()) {
+                    log.warn("Skipping file with null or empty filename");
+                    continue;
+                }
+
+                String lowerFilename = originalFilename.toLowerCase(Locale.ROOT);
+                if (!lowerFilename.endsWith(".svg")) {
+                    log.warn("Skipping non-SVG file: {}", originalFilename);
+                    continue;
+                }
+
+                try {
+                    byte[] fileBytes = inputFile.getBytes();
+                    byte[] sanitizedBytes = svgSanitizer.sanitize(fileBytes);
+                    sanitizedSvgs.add(sanitizedBytes);
+                    filenames.add(Filenames.toSimpleFileName(originalFilename));
+
+                } catch (IOException e) {
+                    log.error(
+                            "SVG sanitization/reading failed for {}: {}",
+                            originalFilename,
+                            e.getMessage());
+                }
+            }
+
+            if (sanitizedSvgs.isEmpty()) {
+                log.error("No valid SVG files were found");
+                return ResponseEntity.status(HttpStatus.BAD_REQUEST)
+                        .body("No valid SVG files were found".getBytes(StandardCharsets.UTF_8));
+            }
+
+            if (combineIntoSinglePdf) {
+                return handleCombinedConversion(sanitizedSvgs, filenames);
+            } else {
+                return handleSeparateConversion(sanitizedSvgs, filenames);
+            }
+
+        } catch (Exception e) {
+            log.error("Unexpected error during SVG to PDF conversion", e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body(
+                            "An unexpected error occurred during conversion"
+                                    .getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    private ResponseEntity<byte[]> handleCombinedConversion(
+            List<byte[]> sanitizedSvgs, List<String> filenames) {
+        try {
+            log.info("Combining {} SVG files into single PDF", sanitizedSvgs.size());
+
+            byte[] pdfBytes = SvgToPdf.combineIntoPdf(sanitizedSvgs);
+
+            if (pdfBytes == null || pdfBytes.length == 0) {
+                log.error("PDF conversion failed - empty output");
+                return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                        .body(
+                                "PDF conversion failed - empty output"
+                                        .getBytes(StandardCharsets.UTF_8));
+            }
+
+            pdfBytes = pdfDocumentFactory.createNewBytesBasedOnOldDocument(pdfBytes);
+
+            String outputFilename =
+                    filenames.isEmpty()
+                            ? "combined_svgs.pdf"
+                            : GeneralUtils.generateFilename(filenames.get(0), "_combined.pdf");
+
+            log.info("Successfully combined {} SVGs into single PDF", sanitizedSvgs.size());
+
+            return WebResponseUtils.bytesToWebResponse(
+                    pdfBytes, outputFilename, MediaType.APPLICATION_PDF);
+
+        } catch (IOException e) {
+            log.error("Error combining SVGs into PDF", e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body(
+                            ("Conversion failed: " + e.getMessage())
+                                    .getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    private ResponseEntity<byte[]> handleSeparateConversion(
+            List<byte[]> sanitizedSvgs, List<String> filenames) {
+        List<ConvertedPdf> convertedPdfs = new ArrayList<>();
+
+        for (int i = 0; i < sanitizedSvgs.size(); i++) {
+            byte[] sanitizedBytes = sanitizedSvgs.get(i);
+            String baseFilename = filenames.get(i);
+
+            try {
+                byte[] pdfBytes = SvgToPdf.convert(sanitizedBytes);
+
+                if (pdfBytes == null || pdfBytes.length == 0) {
+                    log.error("PDF conversion failed - empty output for {}", baseFilename);
+                    continue;
+                }
+
+                pdfBytes = pdfDocumentFactory.createNewBytesBasedOnOldDocument(pdfBytes);
+
+                String outputFilename = GeneralUtils.generateFilename(baseFilename, ".pdf");
+                convertedPdfs.add(new ConvertedPdf(outputFilename, pdfBytes));
+
+                log.info("Successfully converted SVG to PDF: {}", baseFilename);
+
+            } catch (IOException e) {
+                log.error("File processing error for SVG to PDF: {}", baseFilename, e);
+            }
+        }
+
+        if (convertedPdfs.isEmpty()) {
+            log.error("No files were successfully converted");
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("No files were successfully converted".getBytes(StandardCharsets.UTF_8));
+        }
+
+        try {
+            if (convertedPdfs.size() == 1) {
+                ConvertedPdf pdf = convertedPdfs.get(0);
+                return WebResponseUtils.bytesToWebResponse(
+                        pdf.content, pdf.filename, MediaType.APPLICATION_PDF);
+            }
+
+            String zipFilename =
+                    filenames.isEmpty()
+                            ? "converted_svgs.zip"
+                            : GeneralUtils.generateFilename(
+                                    filenames.get(0), "_converted_svgs.zip");
+            byte[] zipBytes = createZipFromPdfs(convertedPdfs);
+
+            return WebResponseUtils.bytesToWebResponse(
+                    zipBytes, zipFilename, MediaType.APPLICATION_OCTET_STREAM);
+        } catch (IOException e) {
+            log.error("Failed to create response", e);
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("Failed to create response".getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    private byte[] createZipFromPdfs(List<ConvertedPdf> pdfs) throws IOException {
+        try (TempFile tempZipFile = new TempFile(tempFileManager, ".zip");
+                ZipOutputStream zipOut =
+                        new ZipOutputStream(Files.newOutputStream(tempZipFile.getPath()))) {
+
+            for (ConvertedPdf pdf : pdfs) {
+                ZipEntry pdfEntry = new ZipEntry(pdf.filename);
+                zipOut.putNextEntry(pdfEntry);
+                zipOut.write(pdf.content);
+                zipOut.closeEntry();
+                log.debug("Added {} to ZIP", pdf.filename);
+            }
+
+            return Files.readAllBytes(tempZipFile.getPath());
+        }
+    }
+
+    private static class ConvertedPdf {
+        final String filename;
+        final byte[] content;
+
+        ConvertedPdf(String filename, byte[] content) {
+            this.filename = filename;
+            this.content = content;
+        }
+    }
+}
@@ -1,7 +1,12 @@
 package stirling.software.SPDF.controller.api.misc;

+import java.io.ByteArrayOutputStream;
 import java.io.IOException;

+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -14,11 +19,11 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;

 import stirling.software.SPDF.model.api.misc.OverlayImageRequest;
+import stirling.software.SPDF.utils.SvgOverlayUtil;
 import stirling.software.common.annotations.AutoJobPostMapping;
 import stirling.software.common.annotations.api.MiscApi;
 import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.util.GeneralUtils;
-import stirling.software.common.util.PdfUtils;
 import stirling.software.common.util.WebResponseUtils;

@MiscApi
@@ -32,25 +37,63 @@ public class OverlayImageController {
    @Operation(
            summary = "Overlay image onto a PDF file",
            description =
-                    "This endpoint overlays an image onto a PDF file at the specified coordinates."
-                            + " The image can be overlaid on every page of the PDF if specified. "
-                            + " Input:PDF/IMAGE Output:PDF Type:SISO")
+                    "This endpoint overlays an image onto a PDF file at the specified coordinates. "
+                            + "Supports both raster formats (PNG, JPEG, etc.) and vector format (SVG). "
+                            + "SVG files are rendered as vector graphics for crisp output at any resolution. "
+                            + "The image can be overlaid on every page of the PDF if specified. "
+                            + "Input:PDF/IMAGE/SVG Output:PDF Type:SISO")
    public ResponseEntity<byte[]> overlayImage(@ModelAttribute OverlayImageRequest request) {
        MultipartFile pdfFile = request.getFileInput();
        MultipartFile imageFile = request.getImageFile();
        float x = request.getX();
        float y = request.getY();
        boolean everyPage = Boolean.TRUE.equals(request.getEveryPage());
+
        try {
            byte[] pdfBytes = pdfFile.getBytes();
            byte[] imageBytes = imageFile.getBytes();
-            byte[] result =
-                    PdfUtils.overlayImage(
-                            pdfDocumentFactory, pdfBytes, imageBytes, x, y, everyPage);
+
+            boolean isSvg = SvgOverlayUtil.isSvgImage(imageBytes);
+
+            PDDocument document = pdfDocumentFactory.load(pdfBytes);
+
+            int pages = document.getNumberOfPages();
+            for (int i = 0; i < pages; i++) {
+                PDPage page = document.getPage(i);
+
+                if (isSvg) {
+                    SvgOverlayUtil.overlaySvgOnPage(document, page, imageBytes, x, y);
+                } else {
+                    try (PDPageContentStream contentStream =
+                            new PDPageContentStream(
+                                    document,
+                                    page,
+                                    PDPageContentStream.AppendMode.APPEND,
+                                    true,
+                                    true)) {
+                        PDImageXObject image =
+                                PDImageXObject.createFromByteArray(document, imageBytes, "");
+                        contentStream.drawImage(image, x, y);
+                        log.info("Image successfully overlaid onto PDF page {}", i);
+                    }
+                }
+
+                if (!everyPage && i == 0) {
+                    break;
+                }
+            }
+
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            document.save(baos);
+            document.close();
+
+            byte[] result = baos.toByteArray();
+            log.info("PDF with overlaid image successfully created");

            return WebResponseUtils.bytesToWebResponse(
                    result,
                    GeneralUtils.generateFilename(pdfFile.getOriginalFilename(), "_overlayed.pdf"));
+
        } catch (IOException e) {
            log.error("Failed to add image to PDF", e);
            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
@@ -0,0 +1,29 @@
+package stirling.software.SPDF.model.api.converters;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Data
+@EqualsAndHashCode
+public class SvgToPdfRequest {
+
+    @Schema(
+            description =
+                    "The SVG file(s) to be converted to PDF. "
+                            + "SVGs are scalable and have inherent dimensions - the conversion uses these dimensions "
+                            + "to determine the PDF page size. If dimensions are not specified in the SVG, A4 size is used.",
+            requiredMode = Schema.RequiredMode.REQUIRED)
+    private MultipartFile[] fileInput;
+
+    @Schema(
+            description =
+                    "Whether to combine all SVG files into a single PDF (each SVG as a separate page) "
+                            + "or create separate PDF files for each SVG.",
+            requiredMode = Schema.RequiredMode.REQUIRED,
+            defaultValue = "false")
+    private Boolean combineIntoSinglePdf;
+}
@@ -14,7 +14,10 @@ import stirling.software.common.model.api.PDFFile;
 public class OverlayImageRequest extends PDFFile {

    @Schema(
-            description = "The image file to be overlaid onto the PDF.",
+            description =
+                    "The image file to be overlaid onto the PDF. "
+                            + "Supports raster formats (PNG, JPEG, etc.) and vector format (SVG). "
+                            + "SVG files are rendered as vector graphics for crisp output at any resolution.",
            requiredMode = Schema.RequiredMode.REQUIRED,
            format = "binary")
    private MultipartFile imageFile;
@@ -0,0 +1,97 @@
+package stirling.software.SPDF.utils;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+
+import org.apache.batik.anim.dom.SAXSVGDocumentFactory;
+import org.apache.batik.bridge.BridgeContext;
+import org.apache.batik.bridge.DocumentLoader;
+import org.apache.batik.bridge.GVTBuilder;
+import org.apache.batik.bridge.UserAgent;
+import org.apache.batik.bridge.UserAgentAdapter;
+import org.apache.batik.gvt.GraphicsNode;
+import org.apache.batik.util.XMLResourceDescriptor;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
+import org.apache.pdfbox.util.Matrix;
+import org.w3c.dom.svg.SVGDocument;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+
+import de.rototor.pdfbox.graphics2d.PdfBoxGraphics2D;
+
+@UtilityClass
+@Slf4j
+public class SvgOverlayUtil {
+
+    public void overlaySvgOnPage(
+            PDDocument document, PDPage page, byte[] svgBytes, float x, float y)
+            throws IOException {
+        try {
+            String parser = XMLResourceDescriptor.getXMLParserClassName();
+            SAXSVGDocumentFactory factory = new SAXSVGDocumentFactory(parser);
+
+            SVGDocument svgDoc;
+            try (ByteArrayInputStream inputStream = new ByteArrayInputStream(svgBytes)) {
+                svgDoc = factory.createSVGDocument("file:///overlay.svg", inputStream);
+            }
+
+            UserAgent userAgent = new UserAgentAdapter();
+            DocumentLoader loader = new DocumentLoader(userAgent);
+            BridgeContext ctx = new BridgeContext(userAgent, loader);
+            ctx.setDynamicState(BridgeContext.DYNAMIC);
+
+            GVTBuilder builder = new GVTBuilder();
+            GraphicsNode rootNode = builder.build(ctx, svgDoc);
+
+            float svgWidth = (float) ctx.getDocumentSize().getWidth();
+            float svgHeight = (float) ctx.getDocumentSize().getHeight();
+
+            PdfBoxGraphics2D pdfGraphics = new PdfBoxGraphics2D(document, svgWidth, svgHeight);
+
+            try {
+                rootNode.paint(pdfGraphics);
+            } finally {
+                pdfGraphics.dispose();
+            }
+
+            PDFormXObject xform = pdfGraphics.getXFormObject();
+
+            try (PDPageContentStream newContentStream =
+                    new PDPageContentStream(
+                            document, page, PDPageContentStream.AppendMode.APPEND, true, true)) {
+                newContentStream.saveGraphicsState();
+
+                newContentStream.transform(new Matrix(1, 0, 0, 1, x, y));
+
+                newContentStream.drawForm(xform);
+
+                newContentStream.restoreGraphicsState();
+            }
+
+            log.info("SVG successfully overlaid as vector graphic at ({}, {})", x, y);
+
+        } catch (Exception e) {
+            log.error("Failed to overlay SVG as vector graphic", e);
+            throw new IOException("SVG overlay failed: " + e.getMessage(), e);
+        }
+    }
+
+    public boolean isSvgImage(byte[] bytes) {
+        if (bytes == null || bytes.length < 5) {
+            return false;
+        }
+        // Check for SVG markers: <?xml or <svg
+        String start =
+                new String(
+                                bytes,
+                                0,
+                                Math.min(200, bytes.length),
+                                java.nio.charset.StandardCharsets.UTF_8)
+                        .toLowerCase();
+        return start.contains("<svg") || (start.contains("<?xml") && start.contains("svg"));
+    }
+}
@@ -0,0 +1,234 @@
+package stirling.software.SPDF.utils;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import org.apache.batik.anim.dom.SAXSVGDocumentFactory;
+import org.apache.batik.bridge.BridgeContext;
+import org.apache.batik.bridge.DocumentLoader;
+import org.apache.batik.bridge.GVTBuilder;
+import org.apache.batik.bridge.UserAgent;
+import org.apache.batik.bridge.UserAgentAdapter;
+import org.apache.batik.gvt.GraphicsNode;
+import org.apache.batik.util.XMLResourceDescriptor;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
+import org.w3c.dom.svg.SVGDocument;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+
+import de.rototor.pdfbox.graphics2d.PdfBoxGraphics2D;
+
+@UtilityClass
+@Slf4j
+public class SvgToPdf {
+
+    /** Default page width in points (A4) */
+    private static final float DEFAULT_PAGE_WIDTH = 595f;
+
+    /** Default page height in points (A4) */
+    private static final float DEFAULT_PAGE_HEIGHT = 842f;
+
+    /** Timeout for SVG rendering in seconds (prevents DoS via complex SVGs) */
+    private static final int RENDERING_TIMEOUT_SECONDS = 30;
+
+    public byte[] convert(byte[] svgBytes) throws IOException {
+        if (svgBytes == null || svgBytes.length == 0) {
+            throw new IOException("SVG input is empty or null");
+        }
+
+        log.debug("Starting SVG to PDF conversion, input size: {} bytes", svgBytes.length);
+
+        try {
+            // 1. Load SVG using Batik
+            String parser = XMLResourceDescriptor.getXMLParserClassName();
+            SAXSVGDocumentFactory factory = new SAXSVGDocumentFactory(parser);
+
+            SVGDocument svgDoc;
+            try (ByteArrayInputStream inputStream = new ByteArrayInputStream(svgBytes)) {
+                svgDoc = factory.createSVGDocument("file:///input.svg", inputStream);
+            }
+
+            // 2. Build the GVT (Graphics Vector Tree) with timeout protection
+            UserAgent userAgent = new UserAgentAdapter();
+            DocumentLoader loader = new DocumentLoader(userAgent);
+            BridgeContext ctx = new BridgeContext(userAgent, loader);
+            ctx.setDynamicState(BridgeContext.DYNAMIC);
+
+            GraphicsNode rootNode = buildGvtWithTimeout(ctx, svgDoc);
+
+            // 3. Get SVG dimensions
+            float width = (float) ctx.getDocumentSize().getWidth();
+            float height = (float) ctx.getDocumentSize().getHeight();
+
+            if (width <= 0) {
+                width = DEFAULT_PAGE_WIDTH;
+                log.warn("SVG width not specified, using default: {}", width);
+            }
+            if (height <= 0) {
+                height = DEFAULT_PAGE_HEIGHT;
+                log.warn("SVG height not specified, using default: {}", height);
+            }
+
+            log.debug("SVG dimensions: {}x{} points", width, height);
+
+            // 4. Create PDF document and render
+            return renderToPdf(rootNode, width, height);
+
+        } catch (Exception e) {
+            log.error("Failed to convert SVG to PDF", e);
+            throw new IOException("SVG to PDF conversion failed: " + e.getMessage(), e);
+        }
+    }
+
+    private GraphicsNode buildGvtWithTimeout(BridgeContext ctx, SVGDocument svgDoc)
+            throws IOException {
+        GVTBuilder builder = new GVTBuilder();
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+
+        Callable<GraphicsNode> buildTask = () -> builder.build(ctx, svgDoc);
+        Future<GraphicsNode> future = executor.submit(buildTask);
+
+        try {
+            return future.get(RENDERING_TIMEOUT_SECONDS, TimeUnit.SECONDS);
+        } catch (TimeoutException e) {
+            future.cancel(true);
+            throw new IOException(
+                    "SVG rendering timed out after "
+                            + RENDERING_TIMEOUT_SECONDS
+                            + " seconds. The SVG may be too complex.");
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IOException("SVG rendering was interrupted", e);
+        } catch (ExecutionException e) {
+            Throwable cause = e.getCause();
+            throw new IOException(
+                    "SVG rendering failed: "
+                            + (cause != null ? cause.getMessage() : e.getMessage()),
+                    cause);
+        } finally {
+            executor.shutdownNow();
+        }
+    }
+
+    private byte[] renderToPdf(GraphicsNode rootNode, float width, float height)
+            throws IOException {
+        try (PDDocument document = new PDDocument();
+                ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
+
+            PDPage page = new PDPage(new PDRectangle(width, height));
+            document.addPage(page);
+
+            // Create and use PdfBoxGraphics2D with proper resource management
+            PdfBoxGraphics2D pdfGraphics = new PdfBoxGraphics2D(document, width, height);
+            try {
+                rootNode.paint(pdfGraphics);
+            } finally {
+                pdfGraphics.dispose();
+            }
+
+            PDFormXObject xform = pdfGraphics.getXFormObject();
+            try (PDPageContentStream contentStream = new PDPageContentStream(document, page)) {
+                contentStream.drawForm(xform);
+            }
+
+            document.save(outputStream);
+
+            byte[] result = outputStream.toByteArray();
+            log.debug("SVG to PDF conversion complete, output size: {} bytes", result.length);
+
+            return result;
+        }
+    }
+
+    public byte[] combineIntoPdf(List<byte[]> svgBytesList) throws IOException {
+        if (svgBytesList == null || svgBytesList.isEmpty()) {
+            throw new IOException("SVG list is empty or null");
+        }
+
+        log.debug("Combining {} SVG files into single PDF", svgBytesList.size());
+
+        try (PDDocument document = new PDDocument();
+                ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
+
+            for (int i = 0; i < svgBytesList.size(); i++) {
+                byte[] svgBytes = svgBytesList.get(i);
+                if (svgBytes == null || svgBytes.length == 0) {
+                    log.warn("Skipping empty SVG at index {}", i);
+                    continue;
+                }
+
+                try {
+                    addSvgAsPage(document, svgBytes);
+                    log.debug("Added SVG {} of {} to combined PDF", i + 1, svgBytesList.size());
+                } catch (Exception e) {
+                    log.error("Failed to add SVG {} to combined PDF: {}", i, e.getMessage());
+                    // Continue with other SVGs
+                }
+            }
+
+            if (document.getNumberOfPages() == 0) {
+                throw new IOException("No SVG files were successfully added to the PDF");
+            }
+
+            document.save(outputStream);
+            byte[] result = outputStream.toByteArray();
+            log.debug(
+                    "Combined SVG to PDF conversion complete, output size: {} bytes",
+                    result.length);
+            return result;
+        }
+    }
+
+    private void addSvgAsPage(PDDocument document, byte[] svgBytes) throws IOException {
+        String parser = XMLResourceDescriptor.getXMLParserClassName();
+        SAXSVGDocumentFactory factory = new SAXSVGDocumentFactory(parser);
+
+        SVGDocument svgDoc;
+        try (ByteArrayInputStream inputStream = new ByteArrayInputStream(svgBytes)) {
+            svgDoc = factory.createSVGDocument("file:///input.svg", inputStream);
+        }
+
+        UserAgent userAgent = new UserAgentAdapter();
+        DocumentLoader loader = new DocumentLoader(userAgent);
+        BridgeContext ctx = new BridgeContext(userAgent, loader);
+        ctx.setDynamicState(BridgeContext.DYNAMIC);
+
+        GraphicsNode rootNode = buildGvtWithTimeout(ctx, svgDoc);
+
+        float svgWidth = (float) ctx.getDocumentSize().getWidth();
+        float svgHeight = (float) ctx.getDocumentSize().getHeight();
+
+        if (svgWidth <= 0) svgWidth = DEFAULT_PAGE_WIDTH;
+        if (svgHeight <= 0) svgHeight = DEFAULT_PAGE_HEIGHT;
+
+        // Use SVG dimensions directly for the PDF page
+        PDPage page = new PDPage(new PDRectangle(svgWidth, svgHeight));
+        document.addPage(page);
+
+        PdfBoxGraphics2D pdfGraphics = new PdfBoxGraphics2D(document, svgWidth, svgHeight);
+        try {
+            rootNode.paint(pdfGraphics);
+        } finally {
+            pdfGraphics.dispose();
+        }
+
+        PDFormXObject xform = pdfGraphics.getXFormObject();
+        try (PDPageContentStream contentStream = new PDPageContentStream(document, page)) {
+            contentStream.drawForm(xform);
+        }
+    }
+}